The blond bombshell of British politics was asked in an interview in The Sunday Times Magazine if he dyed his hair to which the former mayor of London replied that he did.

However, Mr Johnson has now stressed that the grand reveal was nothing more than a joke.

Tim Shipman, the political editor of The Sunday Times who conducted the interview, tweeted that Mr Johnson had requested "an urgent point of clarification" on the issue, insisting he has "never" used hair dye.

Meanwhile, Marina Wheeler, Mr Johnson's wife, told Mr Shipman that she would "stake my life on it and that of my children" that the political heavyweight does not dye his hair.

Mr Johnson's sister, the journalist Rachel Johnson, also came to her brother's defence.

She wrote on Twitter that "no hair dye in the world can achieve the unearthly platinum shine" of his "barnet".

She also insisted that "all Johnsons are natural blondes" while labelling the hair dye "reveal" a "massive headline grabbing wind-up".